Wireless communications networks, such as mobile wireless telephone networks, have become increasingly prevalent over the past decade. A wireless communication network, such as an infrastructure-based wireless network, typically includes a communication network with fixed and wired gateways. Many wireless networks employ a wireless device or terminal which communicates with a base station that is coupled to a wired network. The wireless device can move geographically while it is communicating over a wireless link to the base station. When the wireless device moves out of range of one base station, it may connect or “handoff” (sometimes called “handover”) to a new base station and start communicating with the wired network through the new base station. In order to be ready for a potential handoff, the wireless device may continually background scan for an available base station. Wireless devices have limited energy reserves, however they must actively interface with a network to establish link and transfer data. A network environment in a wireless link is spatial, dynamic, and stochastic. Continually scanning for available base stations may place a strain on the wireless device's energy reserves and increase its power consumption which may further reduce the life span and overall performance of the wireless device.
In addition, the long latency period associated with the handoff is undesirable for wireless devices as this may prevent running of certain applications and interrupt data transfer between the wireless device and the network. The wireless device therefore expends energy and time in establishing and maintaining links prior to and after data transfers. Multimode wireless devices have the additional problem of covering many bands and interfacing with networks asynchronously, thereby adding additional load to the device's energy resources. In some cases, multimode wireless devices may be “blind” for a period of time to all the network services available at a locale. Accordingly there is a need to facilitate the wireless devices to perform fast handoff while optimizing the energy expenditure associated with establishing and monitoring links in wireless networks.
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The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.